Plant volatiles induced by Duponchelia fovealis (Lepidoptera: Crambidae) in two cultivars of strawberry and its attraction to the predator Podisus nigrispinus (Hemiptera: Pentatomidae)

Abstract

Duponchelia fovealis (Lepidoptera: Crambidae) was introduced in Brazil not long ago and causes severe yield losses to strawberry plantations. This situation demands the development of sustainable pest management strategies. Podisus nigrispinus (Hemiptera: Pentatomidae) is a Neotropical generalist predator that has potential to be used in biological control programs against D. fovealis. Herbivore-induced plant volatiles (HIPVs) are of great interest due to their potential uses in pest management programs, particularly for improving biological control. In this way, this study aims at measuring P. nigrispinus response to volatiles induced by D. fovealis-damaged strawberry plants of two cultivars, namely San Andreas and Albion. For this purpose, headspace volatiles emitted by strawberry plants were chemically characterized and behavioral assays of P. nigrispinus nymphs were performed using a Y-tube olfactometer. The two strawberry cultivars, Albion and San Andreas, emitted higher amounts of terpenoids after being exposed to herbivory by D. fovealis. Several compounds were only detected in the headspace of D. fovealis-damaged plants. In spite of some qualitative and quantitative differences, the genotype did not affect the volatile emissions. Podisus nigrispinus showed preference for herbivory-damaged Albion and San Andreas plants in comparison to undamaged plants. However, P. nigrispinus did not prefer herbivore-damaged plants of any cultivar in particular. The results indicate that HIPVs mediate tritrophic signaling in this model system.